Pope Benedict gave this insight into the type of scenario that might not be without some sort of resolution here…
“Those who were married in the Church for the sake of tradition but were not truly believers, and who later find themselves in a new and invalid marriage and subsequently convert, discover faith and feel excluded from the sacrament, are in a particularly painful situation. This really is a cause of great suffering and when I was prefect of the Congregation for the Doctrine of the Faith, I invited various bishops’ conferences and experts to study this problem: a sacrament celebrated without faith. Whether, in fact, a moment of invalidity could be discovered here because the sacrament was found to be lacking a fundamental dimension, I do not dare to say. I personally thought so, but from the discussions we had I realized that it is a highly complex problem and ought to be studied further. But given these people’s painful plight, it must be studied further.”
So the thought is perhaps a “moment of invalidity could be discovered” within the original sacrament.